The explosive issue of immigration is poised to creep back into the Republican primary battle as the candidates prepare to barnstorm South Carolina, one of a handful of states being sued by the federal government for their illegal immigration crackdowns.
While the issue played second fiddle to concerns like jobs and foreign policy in the prior two contests, voters in South Carolina are likely more attuned, given the high-profile lawsuit filed by the U.S. Justice Department.
"That's very much an important issue in South Carolina," said Van Hipp Jr., former chairman of the South Carolina GOP and current chairman of the advocacy group Americans for Securing the Border.
Mitt Romney is charging into the state with arguably the most aggressive message, praising the state's immigration law while trumpeting his own bona fides on the issue.
In a well-timed announcement, the Romney campaign on Wednesday rolled out an endorsement from Kansas Secretary of State Kris Kobach -- the co-author of illegal immigration laws in Arizona and elsewhere. Romney said he wants to work with Kobach to "support states like South Carolina and Arizona that are stepping forward to address this problem."
The campaign also released a statement from Kobach saying Romney would stand "shoulder to shoulder" with states like South Carolina in the illegal immigration fight. Kobach called Romney "the candidate who will finally secure the borders and put a stop to the magnets, like in-state tuition, that encourage illegal aliens to remain in our country unlawfully."
But the candidates -- particularly Romney -- will have to tread carefully as they try to convince South Carolinians that they feel their pain. Next up on the primary calendar is immigrant-heavy Florida. Newt Gingrich offered a blunt warning to Romney -- who has challenged the former House speaker's plan to let some illegal immigrants stay in the country -- during a campaign stop in New Hampshire last weekend.
"I can't wait for them to campaign in Florida," Gingrich said. "Try to go into Miami with the battle cry, 'everybody must go.' ... That is clearly going to come across in the immigrant community as a sign you have no sense of humanity for people."
Romney appears to be taking a dual-track approach. His campaign just released a new Spanish-language TV ad in Florida -- the ad features Cuban-America lawmakers praising Romney in Spanish. Meanwhile, his campaign has tried to exploit perceived weaknesses in his opponents' immigration records.
Kobach's reference to in-state tuition was an apparent shot at Rick Perry's support for offering some young illegal immigrants in-state tuition rates while governor of Texas.
That's not a popular position in South Carolina, according to a poll taken last month by NBC News/Marist. Eighty percent of those polled said it would be "not acceptable" for a GOP presidential nominee to favor in-state rates for illegal immigrants.
The same poll showed greater flexibility on the question of whether it's OK for a nominee to support "limited amnesty." Fifty-three percent said that would be "acceptable," while 41 percent said it would not.
Romney has tried to stake out a distinctly anti-amnesty position. He said last month that he would veto the so-called DREAM Act, a proposal to give some young illegal immigrants a pathway to legal status if they attend college of join the military. Romney also said he'd make illegal immigrants return to their home country in order to get a green card.
That was after Gingrich proposed letting some illegal immigrants with longstanding ties to their communities attain legal status -- though not a pathway to citizenship. Under Gingrich's proposal, a "local citizen panel" would decide whether illegal immigrants who have been in the country 25 years or more should be allowed to stay.
Gingrich has stood by the plan, while rolling out one of the most comprehensive platforms on immigration of any candidate. Under the former House speaker's plan, Homeland Security resources would be shifted to the border, visa rules would be overhauled to make it easier for highly skilled immigrants to work in the country, and the U.S. would set up a legal guest worker program.
Perry, though he doesn't support a border fence across the entire U.S.-Mexico border, stressed at a campaign stop in South Carolina on Tuesday that he's been dealing with illegal immigration in Texas for the past decade. He said laws like the one passed by South Carolina stem from the failure of the federal government to deal with the problem. Perry also has the endorsement of Arizona sheriff Joe Arpaio to help strengthen his immigration message.
Hipp said that while Romney was keen to criticize Perry's immigration positions back when Perry was running strong, Romney might have a harder time spelling out those differences when it comes to Gingrich and Rick Santorum.
Though Gingrich took heat for his "citizen panel" proposal, Hipp gave him credit for signing his group's pledge to support a double fence across the entire U.S.-Mexico border. Hipp said Romney and Santorum are also strong on the fence issue, though they haven't signed the pledge.
Ron Paul, meanwhile, has taken a tough stance by saying he wants to end so-called "birthright citizenship," which allows children born of illegal immigrants on U.S. soil to be automatic citizens.
The immigration issue in South Carolina is not going away any time soon. A federal judge has decided to wait until the Supreme Court weighs in on a separate Arizona challenge before proceeding in the case. The court so far has blocked key provisions of South Carolina's law from going into effect, including a requirement that local officers check immigration status if they suspect someone they pull over is an illegal immigrant.